Devices of the abovementioned kind are known, for example from DE 198 49 153 A1.
Other cleaning devices are disclosed e.g. in DE 195 49 212 A1, DE 91 13 488 U1, DE 92 09 690 U1 or U.S. Pat. No. 5,343,907.
In dispensing systems for beverages, in particular carbonated beverages, it is necessary for hygiene reasons to clean the dispensing system at regular intervals. This cleaning not only involves cleaning the tap, which is usually located in the area of a bar counter in a pub or restaurant, and cleaning the beverage conduit leading to the cellar. Instead, it is also necessary to clean the keg coupler on those surfaces that may come into contact with the beverage.
Keg couplers are of a standardized design on their bottom surface so that, when connecting up a new keg, they can be mounted onto a complementary and also standardized fitting of the keg, and they can be removed from this fitting again upon disconnection of the keg. The actual contact surface of the keg coupler is a radial bearing surface which is mounted onto a corresponding mating surface of the keg fitting, so that the beverage conduit is connected to the riser pipe of the keg.
To fix the coupler on the keg fitting, a bayonet-like arrangement is used which is made up of a cylindrical internal peripheral surface, a lower radial surface, and segmented peripheral surfaces that protrude inward about the circumference. When connecting up a keg, the segments are inserted from above into corresponding recesses of the keg fitting. The keg coupler is then turned about a common axis of keg coupler and keg fitting, so that the segments then extend under corresponding mating segments of the keg fitting and are wedged in place there.
The connecting operation is then effected by pivoting a lever located on the keg coupler. This establishes the connection between a riser pipe of the keg and the beverage conduit leading to a taproom. The pivoting of the lever also opens the gas conduit, so that carrier gas (CO2) can flow into the keg.
Upon connection and disconnection of a keg, it is primarily the radial bearing surface of the keg coupler that comes into contact with the beverage.
In conventional devices of the type mentioned at the outset, the keg coupler is mounted onto the spatially fixed adapter, which in principle is designed as a keg fitting, but instead of having a riser pipe comprises a tubular conduit through which a cleaning liquid can be conveyed. Because conventional cleaning adapters of this kind simulate a connecting of the keg coupler, the gas conduit for the carrier gas has to be shut off before the keg coupler is connected to the cleaning adapter, since otherwise the carrier gas would emerge in an uncontrolled manner.
It should be noted at this point that, in the context of the present application, “cleaning” is to be understood as meaning all processes that can be initiated in connection with a cleaning operation, for example also disinfection, flushing and the like.
Conventional devices of the type mentioned at the outset are now designed such that, during the cleaning on the adapter, only the radial bearing surface is cleaned because, as has been mentioned, when the keg coupler is mounted onto the cleaning adapter, only the connecting process is simulated. Therefore, in conventional cleaning adapters of this kind, only those surfaces and cavities can be cleaned that are also accessible in the connected state of the keg coupler. There is no access, however, to those surfaces which, in contrast to the connected state, cannot be reached through shutting off the gas conduit.
In practice, however, this form of cleaning has not always proven satisfactory under certain operating conditions. This is because, during connection and disconnection of a keg, traces of the beverage may reach the other surfaces of the keg coupler which serve to connect the keg coupler to the keg fitting, that is to say the cylindrical internal peripheral surface, the lower radial surface, and the segmented peripheral surface. These last-mentioned surfaces are not cleaned by conventional devices.
Moreover, even quite negligible traces, for example droplets of beverage, for instance beer, that settle on these surfaces can lead to hygiene problems, especially if the keg is located in a relatively warm environment, for example during the warm season.